User Agent: Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.22 (KHTML, like Gecko) Chrome/25.0.1364.97 Safari/537.22 Steps to reproduce: I used Thunderbird on MS Windows for SMTP AUTH login using PLAIN with a username containing the German umlaut "ü". When I 'm replacing the umlaut with "Ã¼" the login is possible. Actual results: The login failed. Expected results: The login should be possible. According to RFC 4616 the message is encoded using UTF-8. I think Thunderbird is encoding the login string with base64 based on ISO-8859-1 encoded string instead of a UTF-8 encoded string.
Are you indeed using Thunderbird 3.1 as the version stated when you opened this bug? (moving it to MailNews Core makes it the respective Gecko version.)
Hmm, the built-in log omits the username during authentication. Do you have a log somewhere showing the encoding of the username?
I tested it with the current Thunderbird version. In the reject.log of my local Exim the umlaut "ü" in the wrong login is logged as "\374". Exim is logging non-ascii characters in octal form.
That's 0xFC in hex and thus matches "ü" in the ISO 8859-1 table. Thus, it's definitely not UTF-8 what is sent...
I suppose that should be here: http://mxr.mozilla.org/comm-central/source/mailnews/compose/src/nsSmtpProtocol.cpp&rev=9a11f1cc1da9?rev=9a11f1cc1da9#1312 Something there not liking utf-8?